This invention relates generally to a circuit breaker exhibiting a current limiting effect, and more particularly to a circuit breaker having a construction which is suitable for improving the current limiting effect and assembly workability.
An example of circuit breakers exhibiting the current limiting effect in accordance with the prior art is disclosed, for example, in Japanese Utility Model Publication No. 8132/1982. However, none of the prior art circuit breakers pay specific attention to a construction which elongates an arc length at the time of current limiting, nor to the prevention of an insulating property due to deposition of metals contained in arc gas, nor to the improvement in assembly workability.
Another prior art reference, Japanese Utility Model Publication No. 38859/1972, discloses a construction in which an insulating plate is inserted between a fixed contactor and a moving contactor, but the reference does not definitely teach the shape of the insulating plate and its fitting method. An example of such an insulating plate is described in Japanese Utility Model Laid-Open No. 75965/1979. However, since the insulating plate 107' is inserted from a transverse direction as shown in FIG. 74 of the accompanying drawings, one of the sides of a fixed contact 103'a disposed on a fixed contactor 103' is always exposed, so that it is difficult to completely cover the portions which are to be insulated.